From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [ANNOUNCE] 3.0.1-rt8 Date: Tue, 09 Aug 2011 20:47:26 +0200 Message-ID: <1312915646.1083.79.camel@twins> References: <1312580681.28695.44.camel@twins> <4E417D12.70608@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Cc: linux-kernel , Thomas Gleixner , "Paul E. McKenney" , linux-rt-users To: Fernando Lopez-Lezcano Return-path: Received: from casper.infradead.org ([85.118.1.10]:37661 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799Ab1HISrr convert rfc822-to-8bit (ORCPT ); Tue, 9 Aug 2011 14:47:47 -0400 In-Reply-To: <4E417D12.70608@localhost> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Tue, 2011-08-09 at 11:31 -0700, Fernando Lopez-Lezcano wrote: > Hmmm, what are reasonable values for CONFIG_RCU_BOOST_PRIO and > CONFIG_RCU_BOOST_DELAY? (or at least what are you using?). I'm using the defaults, since I haven't actually got a workload besides compiling kernels ;-) Changing these values is very much workload dependent, the PRIO should be high enough not to cause memory starvation, but low enough not to disrupt anything important, and thus completely dependent on you favourite RT workload. The same goes for the DELAY, too long and you run out of memory, too short and you get more overhead, depends on your workload, your machine memory size etc.. Paul should of course be put on trial for giving us these knobs, but seeing where they come from I totally understand they exist ;-)